波纹巴非蛤雌性生殖腺的组织学研究

Histology Studies on the Female Gonad of Paphia (Paratapes ) undulta (Born)

波纹巴非蛤雌性生殖腺中的卵巢由生殖管和输卵管构成．生殖管反复分枝形成生卵小管和其末端膨大的生殖泡囊状结构．卵巢壁薄，由外膜和内生殖上皮组成．外膜主要由结缔组织、单层上皮和薄层肌肉组成，它有许多延伸物伸入卵巢中把卵巢分成一个个不规则小区（即分枝的管状结构，或卵巢小管）．内生殖上皮不断增殖产生生殖带，其中含有卵原细胞等各阶段雌性生殖细胞．卵子的发生可根据卵细胞、细胞核及核仁的大小形态和卵黄积累情况分为：１．卵原细胞期；２．初级卵母细胞期；３．次级卵母细胞期；４．卵黄合成初期卵母细胞；５．卵黄合成中期的卵母细胞；６．卵黄合成后期卵母细胞；７．卵母细胞成熟期．发育早期卵母细胞的核仁出现核仁排出物，较晚期的卵母细胞和成熟卵子的核仁变成双质核仁．本文还报道了波纹巴非蛤卵巢中独特的卵子退化现象．卵巢的发育有季节性的变化．

The histology of female gonad of Paphia (Paratapes) undulata (Born) was studied with light microscope. The female gonad is composed of blanch ovary and oviduct. The ovary consists of great number of branched genital canal and capsules. The histology of ovary is made up of a thin wall which consists of connective tissue and thin layer muscle and endogenic epithelium that grow into germinative zone. The wall extends into ovary and divides it into many small parts, and the germinative zone produces oogonium developing into other female germ cells. According to the size and shape of cells, nuclei and nucleoli, and the vitelline accumulation, the oogenesis can be divided into seven stages: oogonium stage, oocyte I stage, oocyte Ⅱ stage, early vitellogenesis stage, middle vitellogenesis stage, post vitellogenesis stage and mature oocyte stage. In the early and middle developing oocytes, some nucleolar substance, which is considered to be probably related to the formation of yolk within the oocyte, enters into nucleus and cytoplasm. The nucleolus of late developing oocytes and ripe eggs becomes amphinucleous. This paper reports on the results of a study on the retartded egg and degenerated egg in the ovary of the clam. The ovary has a seasonal developing change.